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Background: One of the strategies to preserve genetic material from nonhuman primates (NHP) consists in the implementation of germplasm banks, for future application in reproductive biotechniques, as well as for biomedical research. Based on the success rates achieved in human, there is a prominent possibility to succeed also with NHP. However, studies with NHP are still scarce, especially regarding the cryopreservation of ovarian tissue.Review: Neotropical non-human primates, especially males, have been used in research related to reproductive biotechniques in Brazil. Regarding research on female reproduction and ovarian tissue preservation, most studies were performed using domestic animals as models. Current concepts and controversies in the restoration of gametes in adult females does not exclude the needs to preserve ovarian tissue. Importantly, ovarian tissue can be collected and preserved even after the death of the donors, being applied when finding dead females. Furthermore, collection of ovarian biopsies is also feasible and will not affect reproductive function. Among the cryopreservation methods, the vitrification has been indicated due to practical logistic, as well as because it will avoid the formation of large intracellular ice crystals, and it is claimed that ovarian stromal damage will be decreased under vitrification. Considering the number of threatened prim

RESUMO

Background: One of the strategies to preserve genetic material from nonhuman primates (NHP) consists in the implementation of germplasm banks, for future application in reproductive biotechniques, as well as for biomedical research. Based on the success rates achieved in human, there is a prominent possibility to succeed also with NHP. However, studies with NHP are still scarce, especially regarding the cryopreservation of ovarian tissue.Review: Neotropical non-human primates, especially males, have been used in research related to reproductive biotechniques in Brazil. Regarding research on female reproduction and ovarian tissue preservation, most studies were performed using domestic animals as models. Current concepts and controversies in the restoration of gametes in adult females does not exclude the needs to preserve ovarian tissue. Importantly, ovarian tissue can be collected and preserved even after the death of the donors, being applied when finding dead females. Furthermore, collection of ovarian biopsies is also feasible and will not affect reproductive function. Among the cryopreservation methods, the vitrification has been indicated due to practical logistic, as well as because it will avoid the formation of large intracellular ice crystals, and it is claimed that ovarian stromal damage will be decreased under vitrification. Considering the number of threatened prim

RESUMO

Background: One of the strategies to preserve genetic material from nonhuman primates (NHP) consists in the implementation of germplasm banks, for future application in reproductive biotechniques, as well as for biomedical research. Based on the success rates achieved in human, there is a prominent possibility to succeed also with NHP. However, studies with NHP are still scarce, especially regarding the cryopreservation of ovarian tissue.Review: Neotropical non-human primates, especially males, have been used in research related to reproductive biotechniques in Brazil. Regarding research on female reproduction and ovarian tissue preservation, most studies were performed using domestic animals as models. Current concepts and controversies in the restoration of gametes in adult females does not exclude the needs to preserve ovarian tissue. Importantly, ovarian tissue can be collected and preserved even after the death of the donors, being applied when finding dead females. Furthermore, collection of ovarian biopsies is also feasible and will not affect reproductive function. Among the cryopreservation methods, the vitrification has been indicated due to practical logistic, as well as because it will avoid the formation of large intracellular ice crystals, and it is claimed that ovarian stromal damage will be decreased under vitrification. Considering the number of threatened prim

RESUMO

Background: One of the strategies to preserve genetic material from nonhuman primates (NHP) consists in the implementation of germplasm banks, for future application in reproductive biotechniques, as well as for biomedical research. Based on the success rates achieved in human, there is a prominent possibility to succeed also with NHP. However, studies with NHP are still scarce, especially regarding the cryopreservation of ovarian tissue.Review: Neotropical non-human primates, especially males, have been used in research related to reproductive biotechniques in Brazil. Regarding research on female reproduction and ovarian tissue preservation, most studies were performed using domestic animals as models. Current concepts and controversies in the restoration of gametes in adult females does not exclude the needs to preserve ovarian tissue. Importantly, ovarian tissue can be collected and preserved even after the death of the donors, being applied when finding dead females. Furthermore, collection of ovarian biopsies is also feasible and will not affect reproductive function. Among the cryopreservation methods, the vitrification has been indicated due to practical logistic, as well as because it will avoid the formation of large intracellular ice crystals, and it is claimed that ovarian stromal damage will be decreased under vitrification. Considering the number of threatened prim

RESUMO

Background: One of the strategies to preserve genetic material from nonhuman primates (NHP) consists in the implementation of germplasm banks, for future application in reproductive biotechniques, as well as for biomedical research. Based on the success rates achieved in human, there is a prominent possibility to succeed also with NHP. However, studies with NHP are still scarce, especially regarding the cryopreservation of ovarian tissue.Review: Neotropical non-human primates, especially males, have been used in research related to reproductive biotechniques in Brazil. Regarding research on female reproduction and ovarian tissue preservation, most studies were performed using domestic animals as models. Current concepts and controversies in the restoration of gametes in adult females does not exclude the needs to preserve ovarian tissue. Importantly, ovarian tissue can be collected and preserved even after the death of the donors, being applied when finding dead females. Furthermore, collection of ovarian biopsies is also feasible and will not affect reproductive function. Among the cryopreservation methods, the vitrification has been indicated due to practical logistic, as well as because it will avoid the formation of large intracellular ice crystals, and it is claimed that ovarian stromal damage will be decreased under vitrification. Considering the number of threatened prim

RESUMO

Background: The main advantage of the cryopreservation of ovarian fragments is a thinner tissue, which facilitates the penetration of cryoprotective agents, but the size of tissue may not be a limiting factor in achieving a successful cryopreservation of the ovarian tissue. This information is highly significant considering that the cryopreservation of hemi-ovary or whole ovary may preserve the entire or major part of the contingent of primordial follicles of ovarian fragments. Therefore, the aim of this study was to evaluate the vitrification of different dimensions goat ovarian tissue on the follicular morphology, viability, diameter, and the stromal cell density. Materials, Methods & Results: The ovarian tissue was vitrified as fragment, hemi-ovary, or whole ovary, and after warming, the preantral follicles were examined by trypan blue dye exclusion test and histological analysis. Preantral follicles incubated with trypan blue were considered viable if the oocyte and granulosa cells remained unstained. Preantral follicles were classified as morphologically normal only when they contained intact oocyte and granulosa cells. The follicular diameter was measured considering the major and minor axes of each follicle; the average of these 2 measurements was used to determine the diameter of each follicle. Ovarian stroma cells density was evaluated by calculating the number of

Background: The main advantage of the cryopreservation of ovarian fragments is a thinner tissue, which facilitates the penetration of cryoprotective agents, but the size of tissue may not be a limiting factor in achieving a successful cryopreservation of the ovarian tissue. This information is highly significant considering that the cryopreservation of hemi-ovary or whole ovary may preserve the entire or major part of the contingent of primordial follicles of ovarian fragments. Therefore, the aim of this study was to evaluate the vitrification of different dimensions goat ovarian tissue on the follicular morphology, viability, diameter, and the stromal cell density. Materials, Methods & Results: The ovarian tissue was vitrified as fragment, hemi-ovary, or whole ovary, and after warming, the preantral follicles were examined by trypan blue dye exclusion test and histological analysis. Preantral follicles incubated with trypan blue were considered viable if the oocyte and granulosa cells remained unstained. Preantral follicles were classified as morphologically normal only when they contained intact oocyte and granulosa cells. The follicular diameter was measured considering the major and minor axes of each follicle; the average of these 2 measurements was used to determine the diameter of each follicle. Ovarian stroma cells density was evaluated by calculating the number of

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Background: The anti-müllerian hormone (AMH) is a member of the transforming growth factor (TGF-) superfamily, which exerts important functions on local regulation of folliculogenesis. Although in vivo and in vitro studies suggest that AMH affects the primordial follicle assembly and activation, as well as the responsiveness of growing follicles to folliclestimulating hormone (FSH), the physiological mechanisms involved in these actions remain to be fully elucidated. Given the relevance of AMH in the folliculogenesis, this review aimed to describe the structural features, expression and the main biological effects of AMH on the follicular development. Review: Originally identified as a testicular product, AMH is responsible for regression of the Müllerian ducts during sexual differentiation of male embryos. In females, AMH is produced almost exclusively by granulosa cells of ovarian growing follicles, whose serum levels are positively related to the number of ovarian follicles, making AMH an excellent clinic marker of ovarian reserve. Along this work, it was shown aspects related to the structural characterization of AMH and its specific type II receptor (AMHRII). AMH is a glycoprotein dimer linked by disulfide bonds. The mature protein comprises two unequal domains: a long N-terminal domain (110-kDa) and a short C-terminal domain (25-kDa), responsible for the biological act

A foliculogênese é um evento complexo que envolve o recrutamento do pool de folículos primordiais, seguido por uma fase de crescimento e diferenciação. É sabido que para a sua regulação são requeridos vários fatores parácrinos e autócrinos, especialmente fatores de crescimento produzidos pelas células da granulosa. Dentre esses fatores, destaca-se o hormônio anti-mülleriano (AMH), uma glicoproteína membro da superfamília de fatores de crescimento transformantes (TGF-). Inicialmente o AMH foi estudado por seu papel regulatório no processo de diferenciação sexual masculina. [...]

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Background: The anti-müllerian hormone (AMH) is a member of the transforming growth factor (TGF-) superfamily, which exerts important functions on local regulation of folliculogenesis. Although in vivo and in vitro studies suggest that AMH affects the primordial follicle assembly and activation, as well as the responsiveness of growing follicles to folliclestimulating hormone (FSH), the physiological mechanisms involved in these actions remain to be fully elucidated. Given the relevance of AMH in the folliculogenesis, this review aimed to describe the structural features, expression and the main biological effects of AMH on the follicular development. Review: Originally identified as a testicular product, AMH is responsible for regression of the Müllerian ducts during sexual differentiation of male embryos. In females, AMH is produced almost exclusively by granulosa cells of ovarian growing follicles, whose serum levels are positively related to the number of ovarian follicles, making AMH an excellent clinic marker of ovarian reserve. Along this work, it was shown aspects related to the structural characterization of AMH and its specific type II receptor (AMHRII). AMH is a glycoprotein dimer linked by disulfide bonds. The mature protein comprises two unequal domains: a long N-terminal domain (110-kDa) and a short C-terminal domain (25-kDa), responsible for the biological act

A foliculogênese é um evento complexo que envolve o recrutamento do pool de folículos primordiais, seguido por uma fase de crescimento e diferenciação. É sabido que para a sua regulação são requeridos vários fatores parácrinos e autócrinos, especialmente fatores de crescimento produzidos pelas células da granulosa. Dentre esses fatores, destaca-se o hormônio anti-mülleriano (AMH), uma glicoproteína membro da superfamília de fatores de crescimento transformantes (TGF-). Inicialmente o AMH foi estudado por seu papel regulatório no processo de diferenciação sexual masculina. [...]

RESUMO

Background: The main advantage of the cryopreservation of ovarian fragments is a thinner tissue, which facilitates the penetration of cryoprotective agents, but the size of tissue may not be a limiting factor in achieving a successful cryopreservation of the ovarian tissue. This information is highly significant considering that the cryopreservation of hemi-ovary or whole ovary may preserve the entire or major part of the contingent of primordial follicles of ovarian fragments. Therefore, the aim of this study was to evaluate the vitrification of different dimensions goat ovarian tissue on the follicular morphology, viability, diameter, and the stromal cell density. Materials, Methods & Results: The ovarian tissue was vitrified as fragment, hemi-ovary, or whole ovary, and after warming, the preantral follicles were examined by trypan blue dye exclusion test and histological analysis. Preantral follicles incubated with trypan blue were considered viable if the oocyte and granulosa cells remained unstained. Preantral follicles were classified as morphologically normal only when they contained intact oocyte and granulosa cells. The follicular diameter was measured considering the major and minor axes of each follicle; the average of these 2 measurements was used to determine the diameter of each follicle. Ovarian stroma cells density was evaluated by calculating the number of

Background: The main advantage of the cryopreservation of ovarian fragments is a thinner tissue, which facilitates the penetration of cryoprotective agents, but the size of tissue may not be a limiting factor in achieving a successful cryopreservation of the ovarian tissue. This information is highly significant considering that the cryopreservation of hemi-ovary or whole ovary may preserve the entire or major part of the contingent of primordial follicles of ovarian fragments. Therefore, the aim of this study was to evaluate the vitrification of different dimensions goat ovarian tissue on the follicular morphology, viability, diameter, and the stromal cell density. Materials, Methods & Results: The ovarian tissue was vitrified as fragment, hemi-ovary, or whole ovary, and after warming, the preantral follicles were examined by trypan blue dye exclusion test and histological analysis. Preantral follicles incubated with trypan blue were considered viable if the oocyte and granulosa cells remained unstained. Preantral follicles were classified as morphologically normal only when they contained intact oocyte and granulosa cells. The follicular diameter was measured considering the major and minor axes of each follicle; the average of these 2 measurements was used to determine the diameter of each follicle. Ovarian stroma cells density was evaluated by calculating the number of

RESUMO

Background: Cryopreservation is a biotech successfully employed in female gametes and embryos. This technique is of great importance for propagation of genetic material from animals with high-value livestock as well as to preserve the fertility of women undergoing cancer treatments. However, low temperatures can result in damage to different cellular compartments and organelles. This damage culminates in reduced viability, since they affect cell metabolism.Review: Cryopreservation consists of maintenance of biological material at low temperatures, in which chemical reactions are ceased, however, allowing the cells to preserve their viability. However, the decrease of temperature and subsequent warming may result in cellular damage. These damages occur in the cell membrane, cytoplasmic organelles and the cell nucleus. It is believed that the fi rst cell structure undergoing cryoinjury is the plasma membrane, responsible for maintaining homeostasis within the cell, and the loss of plasma membrane during the reduction temperature reported the main damage. The membrane damage due to cryopreservation appears to correlate with the reduction of thermal energy at low temperatures, thus limiting the movement of molecules through the phospholipids of lipid bilayer. Cryopreservation also alters the morphology, structure and cellular distribution of lipid droplets, reducing the survival of

Background: Cryopreservation is a biotech successfully employed in female gametes and embryos. This technique is of great importance for propagation of genetic material from animals with high-value livestock as well as to preserve the fertility of women undergoing cancer treatments. However, low temperatures can result in damage to different cellular compartments and organelles. This damage culminates in reduced viability, since they affect cell metabolism.Review: Cryopreservation consists of maintenance of biological material at low temperatures, in which chemical reactions are ceased, however, allowing the cells to preserve their viability. However, the decrease of temperature and subsequent warming may result in cellular damage. These damages occur in the cell membrane, cytoplasmic organelles and the cell nucleus. It is believed that the fi rst cell structure undergoing cryoinjury is the plasma membrane, responsible for maintaining homeostasis within the cell, and the loss of plasma membrane during the reduction temperature reported the main damage. The membrane damage due to cryopreservation appears to correlate with the reduction of thermal energy at low temperatures, thus limiting the movement of molecules through the phospholipids of lipid bilayer. Cryopreservation also alters the morphology, structure and cellular distribution of lipid droplets, reducing the survival of

RESUMO

Background: Cryopreservation is a biotech successfully employed in female gametes and embryos. This technique is of great importance for propagation of genetic material from animals with high-value livestock as well as to preserve the fertility of women undergoing cancer treatments. However, low temperatures can result in damage to different cellular compartments and organelles. This damage culminates in reduced viability, since they affect cell metabolism.Review: Cryopreservation consists of maintenance of biological material at low temperatures, in which chemical reactions are ceased, however, allowing the cells to preserve their viability. However, the decrease of temperature and subsequent warming may result in cellular damage. These damages occur in the cell membrane, cytoplasmic organelles and the cell nucleus. It is believed that the fi rst cell structure undergoing cryoinjury is the plasma membrane, responsible for maintaining homeostasis within the cell, and the loss of plasma membrane during the reduction temperature reported the main damage. The membrane damage due to cryopreservation appears to correlate with the reduction of thermal energy at low temperatures, thus limiting the movement of molecules through the phospholipids of lipid bilayer. Cryopreservation also alters the morphology, structure and cellular distribution of lipid droplets, reducing the survival of

Background: Cryopreservation is a biotech successfully employed in female gametes and embryos. This technique is of great importance for propagation of genetic material from animals with high-value livestock as well as to preserve the fertility of women undergoing cancer treatments. However, low temperatures can result in damage to different cellular compartments and organelles. This damage culminates in reduced viability, since they affect cell metabolism.Review: Cryopreservation consists of maintenance of biological material at low temperatures, in which chemical reactions are ceased, however, allowing the cells to preserve their viability. However, the decrease of temperature and subsequent warming may result in cellular damage. These damages occur in the cell membrane, cytoplasmic organelles and the cell nucleus. It is believed that the fi rst cell structure undergoing cryoinjury is the plasma membrane, responsible for maintaining homeostasis within the cell, and the loss of plasma membrane during the reduction temperature reported the main damage. The membrane damage due to cryopreservation appears to correlate with the reduction of thermal energy at low temperatures, thus limiting the movement of molecules through the phospholipids of lipid bilayer. Cryopreservation also alters the morphology, structure and cellular distribution of lipid droplets, reducing the survival of

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The leukemia inhibitory factor (LIF) is a glycoprotein from the interleukin-6 family, which acts with its membrane receptors in different biological processes. Studies have reported the involvement of this factor during ovarian follicular development and embryo implantation in mammals. This review summarizes the main aspects of the molecular structure of LIF, its receptors, mechanisms of action, expression and functions focusing on ovarian physiology and embryo implantation. Keywords: LIF, ovarian, follicle, endometrium, mammalian.

O fator inibidor de leucemia (LIF) é uma glicoproteína pertencente à família das interleucinas-6 que ligados aos seus receptores intermembranários atua em diferentes processos biológicos. Estudos têm relatado a participação deste fator durante o desenvolvimento folicular ovariano e implantação em mamíferos. Esta revisão resume os principais aspectos da estrutura molecular do LIF, seus receptores, mecanismos de ação, expressão e funções focando na fisiologia ovariana e implantação embrionária. Palavras-Chave: LIF, ovário, folículo, endométrio, mamífero.

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Vitrification is a cryopreservation methods cheap, fast and easy to perform and has been used, with relatively success, for the preservation of embryos and oocytes from preantral and antral follicles. The present review describes the different methods of vitrification, the main results obtained so far as well as its important for the assisted reproduction technologies in human, genetic superior animal and endangered mammalian species. Keywords: Blastocyst, oocyte, preantral follicle, cryopreservation.

A vitrificação é um método de criopreservação barato, rápido e fácil de ser realizado e tem sido usado com relativo sucesso para a preservação de embriões e oócitos obtidos a partir de folículos antrais e pré-antrais. A presente revisão descreve os diferentes métodos de vitrificação, os principais resultados obtidos, bem como sua importância para a tecnologia de reprodução assistida em humanos, animais de genética superior e espécies mamíferas ameaçadas de extinção. Palavras-Chave: Blastocisto, oócito, folículo ovariano pré-antral, criopreservação.

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The preantral follicles enclosed in ovarian cortex represent about 95% of the entire follicular population and can be grown and matured in vitro in order to obtain mature and competent oocytes, which may be used in various reproductive biotechnologies applied to domestic animals. Studies related to folliculogenesis can be performed in vivo, by analyzing the expression of genes or proteins that are present in the ovary, and also in vitro with the use of different systems, in which the follicles can be grown in situ or isolated. Thus, this study shows the different methods of isolation and in vitro systems employed for maintaining the structural integrity and development of preantral follicles. Keywords: Biotechnology, development, folliculogenesis.

Os folículos pré-antrais presentes no córtex ovariano representam cerca de 95% de toda a população folicular e podem ser crescidos e maturados in vitro, visando a obtenção posterior de oócitos maturos e competentes, os quais poderão ser utilizados nas diversas biotécnicas da reprodução aplicadas aos animais domésticos. Os estudos relacionados com a foliculogênese podem ser feitos in vivo, através da análise de expressão de genes ou proteínas que estão presentes no ovário, e ainda in vitro com a utilização de diferentes sistemas, onde os folículos podem ser cultivados in situ ou isolados. Deste modo, neste trabalho foram abordados os diferentes métodos de isolamento e sistemas de cultivo in vitro empregados para a manutenção da integridade estrutural e desenvolvimento de folículos pré-antrais. Palavras-Chave: Biotécnicas, desenvolvimento, foliculogênese.

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The reproductive activity of mammalian species can be related to the most propitious time of the year to the birth of offspring. The light period duration (photoperiod) is strongly related to this mechanism through the secretion of melatonin by pineal gland. Melatonin is the neurotransmitter responsible for mediate the daily information of light/dark cycle, informing the night duration to the body and, consequently the corresponding time of the year. The presence of melatonin receptor sites in the hypothalamus and the pituitary gland explain its effects on the secretion of pituitary hormones (Follicle stimulating hormone-FSH and Luteinizing hormone-LH) and seasonal rhythm organization. In addition to its systemic action, reports have demonstrated an influence in the ovarian physiology, since high levels in follicular fluid were detected and the presence of melatonin receptors in the ovarian cells has been found. Also, its important function as an antioxidant can influence follicular growth, oocyte maturation, ovulation and luteal function. The purpose of this article is to review the melatonin influence in the animal reproduction, especially in the ovarian physiology. Keywords: Photoperiod, folliculogenesis, antioxidant.

A atividade reprodutiva das espécies mamíferas pode ser relacionada ao período do ano mais propício para o nascimento das crias. A duração do período de luz (fotoperíodo) está fortemente relacionada a esse mecanismo por intermédio da secreção de melatonina pela glândula pineal. A melatonina é o neurotransmissor responsável por mediar às informações diárias do ciclo de luz/escuridão, informando ao organismo a duração da noite e, conseqüentemente, o período do ano correspondente. A presença de seus receptores em células hipotalâmicas e células gonadotróficas da hipófise explicam os efeitos da melatonina na secreção de gonadotrofinas (Hormônio folículo estimulante-FSH e Hormônio luteinizante-LH) e na organização dos ritmos sazonais. Além da sua atuação sistêmica, estudos têm sugerido uma atuação deste hormônio na fisiologia ovariana, uma vez que foram detectadas altas concentrações de melatonina no fluido folicular e a presença de seus receptores em células foliculares. Além disso, a sua atuação como antioxidante pode estar associada a vários eventos como o desenvolvimento folicular, a maturação oocitária, a ovulação e a função luteal. Dessa forma, a presente revisão fará uma abordagem geral da influência da melatonina na reprodução animal, enfatizando suas ações sobre a fisiologia ovariana. Palavras-Chave: Fotoperíodo, foliculogênese, antioxidante.

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Background:  :  :      : The platelet-derived growth factor (PDGF) is expressed in a wide variety of cell types, exerts a potent mitogenic role and acts on the growth, differentiation and cell chemotaxis. Studies have shown that during folliculogenesis, PDGF and their receptors are expressed in oocytes, granulosa cells and thecal cells of ovarian follicles at different developmental stages in several species. Although exist many information about its expression sites, as well as about its action in different cells types, the role of PDGF on ovarian folliculogenesis remains understudied. Thus, this article aims to review issues related to PDGF, suggesting the involvement of this mitogenic factor during follicular development. Review: Along this work, it was shown aspects related to structural characterization of PDGF and its receptors, as well as PDGF expression in different cells types, emphasizing its importance to follicular development. PDGF family is composed by four polypeptide chains (each encoded by a different gene), which are synthesized in the form of inactive pro-proteins. After a proteolytic processing, these chains undergo homo or heterodimerization, resulting in five isoforms (PDGF-AA, -BB, -AB, -CC e -DD). The cellular effects of these different PDGF isoforms are mediated by binding, with different specificities, to three transmembrane receptors isoforms of type

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Background:  :  :      : The platelet-derived growth factor (PDGF) is expressed in a wide variety of cell types, exerts a potent mitogenic role and acts on the growth, differentiation and cell chemotaxis. Studies have shown that during folliculogenesis, PDGF and their receptors are expressed in oocytes, granulosa cells and thecal cells of ovarian follicles at different developmental stages in several species. Although exist many information about its expression sites, as well as about its action in different cells types, the role of PDGF on ovarian folliculogenesis remains understudied. Thus, this article aims to review issues related to PDGF, suggesting the involvement of this mitogenic factor during follicular development. Review: Along this work, it was shown aspects related to structural characterization of PDGF and its receptors, as well as PDGF expression in different cells types, emphasizing its importance to follicular development. PDGF family is composed by four polypeptide chains (each encoded by a different gene), which are synthesized in the form of inactive pro-proteins. After a proteolytic processing, these chains undergo homo or heterodimerization, resulting in five isoforms (PDGF-AA, -BB, -AB, -CC e -DD). The cellular effects of these different PDGF isoforms are mediated by binding, with different specificities, to three transmembrane receptors isoforms of type

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Several cellular processes, such as cell survival, proliferation, differentiation, adhesion and migration, are controlled by a variety of growth factors. Among these factors it is possible to highlight the epidermal growth factor (EGF) family, which is constituted of at least eight members, described as important mediators of ovarian function. Its action on the follicular and embryo development is mediated by tyrosina kinase transmembrane receptors that are able to interact with at least six different members of this family. This paper aims focus on the role of EGF family on follicular and embryonic development in mammals. Keywords: EGF, tyrosine kinases receptor, ovarian follicle.

Diversos processos celulares, tais como a sobrevivência, proliferação, diferenciação, adesão e migração celular, são controlados por uma variedade de fatores de crescimento. Dentre estes fatores destaca-se a família do fator de crescimento epidermal (EGF), que é constituída de pelo menos oito membros, descritos como importantes mediadores da função ovariana. Sua ação no desenvolvimento folicular e embrionário é mediada por receptores transmembranários do tipo tirosina quinase, capazes de interagir com pelo menos seis diferentes membros desta família. O presente trabalho tem como objetivo abordar o papel da família EGF no desenvolvimento folicular e embrionário em mamíferos. Palavras-Chave: EGF, receptor tirosina quinase, folículo ovariano.

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Objetivo: Divulgar la biotécnica exponiendo algunos de sus aspectos y abordar sus principales etapas, el aislamiento, la criopreservación y el cultivo. Fuentes Consultadas: La información se obtuvo de CAB, MEDLINE, PUBMED, Science Direct y el Portal CAPES. Síntesis de los Datos: Los foliculos preantrales guardan aproximadamente el 90% de los oocitos que están presentes en el ovario. Esta biotécnica consiste en rescatar oocitos inmaduros retenidos en los foliculos preantrales antes de que ocurra el proceso de atresia. Por la criopreservación de las células es posible constituir bancos de germoplasma, y preservar e/ material genético de mujeres que se sometieron a la quimio y/o radioterapia as; como de animales en extinción. Conclusiones: AI ser una biotécnica reciente, sus aplicaciones se restringen a la investigación básica. Se requieren más estudios para perfeccionar sus etapas.

Objective: To disclose a new biotechnique, listing some of its aspects and addressing its main stages, isolation, cryopreservation and culture of preantral follicles. Data Sources: The information was obtained from CAB, MEDLINE, PUBMED, Science Direct and CAPES Portal. Data Synthesis: The preantral follicles store about 90% of the oocytes within the ovary. The biotechnique described is based on recovering immature oocytes retained inside preantral follicles before atresia takes place. The cryopreservation of these cells enables the creation of germoplasm banks, preserving the genetic material of women submitted to chemotherapy and/or radiotherapy, as well as that endangered animal species. Conclusions: Being a recent biotechnique, its application is restricted to basic research. Additional studies are required lo improve the stages involved.

Objetivo: Divulgar a biotécnica relacionando alguns de seus aspectos, bem como abordar suas principais etapas, o isolamento, a criopreservação e o cultivo. Fontes Consultadas: O levantamento das informações foi realizado no CAB, MEDLINE, PUBMED, Science Direct e Portal CAPES. Síntese dos Dados: Os folículos pré-antrais armazenam cerca de 90% dos oócitos presentes no ovário. Essa biotécnica consiste em recuperar oócitos imaturos retidos no interior de folículos pré-antrais antes de ocorrer o processo de atresia. Pela criopreservação destas células, é possível montar bancos de gerrnoplasma preservando material genético de mulheres submetidas à quimio e/ou à radioterapia, e de animais em via de extinção. Conclusões: Por ser uma biotécnica recente, sua aplicação é restrita à pesquisa fundamental, sendo ainda necessário mais estudos para aprimorar suas etapas. 

RESUMO

Objetivo: Divulgar la biotécnica exponiendo algunos de sus aspectos y abordar sus principales etapas, el aislamiento, la criopreservación y el cultivo. Fuentes Consultadas: La información se obtuvo de CAB, MEDLINE, PUBMED, Science Direct y el Portal CAPES. Síntesis de los Datos: Los foliculos preantrales guardan aproximadamente el 90% de los oocitos que están presentes en el ovario. Esta biotécnica consiste en rescatar oocitos inmaduros retenidos en los foliculos preantrales antes de que ocurra el proceso de atresia. Por la criopreservación de las células es posible constituir bancos de germoplasma, y preservar e/ material genético de mujeres que se sometieron a la quimio y/o radioterapia as; como de animales en extinción. Conclusiones: AI ser una biotécnica reciente, sus aplicaciones se restringen a la investigación básica. Se requieren más estudios para perfeccionar sus etapas.

Objective: To disclose a new biotechnique, listing some of its aspects and addressing its main stages, isolation, cryopreservation and culture of preantral follicles. Data Sources: The information was obtained from CAB, MEDLINE, PUBMED, Science Direct and CAPES Portal. Data Synthesis: The preantral follicles store about 90% of the oocytes within the ovary. The biotechnique described is based on recovering immature oocytes retained inside preantral follicles before atresia takes place. The cryopreservation of these cells enables the creation of germoplasm banks, preserving the genetic material of women submitted to chemotherapy and/or radiotherapy, as well as that endangered animal species. Conclusions: Being a recent biotechnique, its application is restricted to basic research. Additional studies are required lo improve the stages involved.

Objetivo: Divulgar a biotécnica relacionando alguns de seus aspectos, bem como abordar suas principais etapas, o isolamento, a criopreservação e o cultivo. Fontes Consultadas: O levantamento das informações foi realizado no CAB, MEDLINE, PUBMED, Science Direct e Portal CAPES. Síntese dos Dados: Os folículos pré-antrais armazenam cerca de 90% dos oócitos presentes no ovário. Essa biotécnica consiste em recuperar oócitos imaturos retidos no interior de folículos pré-antrais antes de ocorrer o processo de atresia. Pela criopreservação destas células, é possível montar bancos de gerrnoplasma preservando material genético de mulheres submetidas à quimio e/ou à radioterapia, e de animais em via de extinção. Conclusões: Por ser uma biotécnica recente, sua aplicação é restrita à pesquisa fundamental, sendo ainda necessário mais estudos para aprimorar suas etapas.